Display screen or portion thereof with a payday forecast graphical user interface



The sole FIGURE illustrates a front view of a display screen or portion thereof with a payday forecast graphical user interface (GUI), wherein parts of the GUI are shown in broken lines for illustrative purposes;

The rectangular dot-dash broken-line perimeter illustrates a display screen. The dashed broken lines outside this perimeter illustrate portions of an electronic device. The dashed broken lines within the perimeter illustrate portions of a graphical user interface. The broken lines form no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with a payday forecast graphical user interface, as shown and described. 